Investigating Productivity of Modular Buildings

The modular construction industry has grown substantially, yet understanding of the relationships between project categories, sizes, and productivity remains limited. This study investigates these relationships in both permanent and relocatable modular construction projects across different sectors, including multifamily housing, dormitories, healthcare, education, retail, office, and workforce housing. Data from 303 permanent and 188 relocatable projects in the Modular Building Institute database were analyzed using Kendall's tau-b correlation and linear regression analyses. Key findings reveal that permanent projects outnumber and are generally larger than relocatable ones, with education being the most common project type. Significant positive correlations between project size and productivity were found in most categories, with workforce housing showing the highest productivity rates. Productivity varied widely, ranging from 50 to 165.7 square feet per day. The correlation was stronger in permanent structures compared to relocatable ones, with significant positive correlations observed in all permanent categories except hotels, and in all relocatable categories except healthcare and retail. This study contributes to the body of knowledge by providing empirical evidence of productivity trends across different modular construction types and sizes. For practice, it offers tools for productivity forecasting and project selection, highlighting the potential benefits of larger modular projects. These insights can guide strategic decision-making in project portfolio management, potentially leading to improved overall productivity and efficiency in modular construction operations.